text: Alternatives to acid–base extraction include:
  * Filtering the mixture through a plug of silica gel or alumina — if the product is a charged salt, it will remain strongly adsorbed to the silica gel or alumina.
  * Ion exchange chromatography can separate acids, bases, or mixtures of strong and weak acids and bases by their varying affinities to the column medium at different pH.
  * Using column chromatography to separate the neutral compounds according to their ratio-of-fronts values.
  * Gel electrophoresis, which separates large biomolecules based on their charge and size.